This disclosure relates to a sheet stacking device for stacking sheets, a sheet post-processing device which includes the sheet stacking device, and an image forming apparatus.
There has been known a sheet post-processing device which includes a post-processing mechanism for applying staple processing, hole forming processing or the like to a sheet after an image is formed on the sheet. The sheet post-processing device includes a sheet stacking device which includes: a pair of sheet discharge rollers for discharging a sheet to which post-processing is applied; and a stacking tray which receives the sheet discharged by the pair of sheet discharge rollers and stacks the sheet thereon. As the sheet stacking device of this type, there has been known a sheet stacking device which includes a rear end beating member which beats a rear end portion of the sheet which passes through the pair of sheet discharge rollers so as to make the sheet fall on the stacking tray and presses the rear end portion of the sheet which falls on the stacking tray.
In one prior art, a pressing member which functions as a rear end beating member is configured to be rotatable about a shaft disposed below a rotary shaft of a drive roller of a pair of sheet discharge rollers. The pressing member and the drive roller are rotatably driven by drive motors which form separate bodies respectively. As the pressing member rotates about an axis due to a drive force from the drive motor, the pressing member beats and presses the rear end portion of the sheet which passes through the pair of sheet discharge rollers.
In another prior art, a scrape member which functions as a rear end beating member is configured to be disposed on a rotary shaft of a driven roller of a pair of sheet discharge rollers, and to be driven to rotate by a sheet which is discharged from the pair of sheet discharge rollers. The scrape member has a plurality of flexible blade members. Due to the driven rotation of the scrape member in response to discharging of the sheet from the pair of sheet discharge rollers, the plurality of blade members beat and press a rear end portion of the sheet which passes through the pair of sheet discharge rollers.